According to the prior art, measurements made from the surface of the head in particular are made using silver electrodes for measuring electrical responses, for example, in TMS (transcranial magnetic stimulation) tests, in which an electromagnetic pulse is directed to the brain and the response it creates is measured using electroencephalograph (EEG) measuring equipment. In practice, electrically polarizing interfaces arise between the different materials in the silver electrodes according to the prior art and lead to interference signals that diminish the accuracy of the measurement.
The silver electrodes are chloridized, in an attempt to eliminate this phenomenon. Despite this measure, satisfactory results are not always achieved. As chloridization only affects the surface of the electrode, it is easily removed by wear or, for example, by unintentionally scratching the electrode. Chloridization must be performed regularly between measurements, leading to additional work and preventing continuous use of the electrodes.
In measurement caps according to the prior art, the electrode structures become detached easily during washing and are difficult to reattach.